GENERAL ACCOUNT OF BUTTERFLIES 



All insects in the course of their development 

 shed their skin at regular intervals. This process 

 is termed molting, and the cast skin is referred to 

 as the exuvice (ex-u'vi-ae). 



Before an insect molts a new skin is formed 

 beneath the old one ; then the old skin bursts 

 open, and the insect crawls forth, clothed in a soft 

 skin, which stretches, if necessary, to accommo- 

 date the increased size of the insect. Very soon, 

 however, this new skin becomes hard. Caterpil- 

 lars molt four or five times during their larval life ; 

 some other insects molt many more times. 



When a caterpillar is full-grown it makes 

 preparation for the quiet period that is to follow. 

 The larvae of some moths go into the ground and 

 form a cell within which the pupa state is passed; 

 the larva; of others spin a dense silken case about 

 the body which is known as the cocoon ; some of 

 these cocoons are familiar objects. The larvae of 

 skippers, which are commonly classed with but- 

 terflies (see Part III), spin a cocoon ; but almost 

 no true butterflies do so. 



A few butterflies undergo their transforma- 

 tions in a crevice or cell upon or in the ground ; 

 but nearly all species fasten themselves to some 

 object and hang suspended during the pupa stage. 



There are two distinct methods of suspension; 



